Sophy Ridge

Political Correspondent

Opinion in Westminster is shifting towards military intervention in Iraq.

Of the MPs I have spoken to, 15 have said they would support it compared to just three who would be against.

This poses a dilemma for the Prime Minister.

After the bloody, protracted conflicts in Afghanistan and Iraq – wars with no clear aim or end point – the British and American public are scarred by the solemn lines of coffins containing servicemen and women coming home to be buried.

Rather than being proud to be the policemen of the world, there is a new scepticism about whether the West can make a difference (except for the worst.)

Make no mistake – if David Cameron can find a way to avoid British combat troops going into Iraq, he will.

The number of soldiers killed in Iraq and Afghanistan has been immense

MPs on both sides of the House are appalled by the thousands of people trapped on the bleak mountains in Iraq or – worse – butchered and buried in make shift graves.

Conservative MPs in particular are demanding the Prime Minister recall Parliament to debate whether the UK should be involved in air strikes against IS or arming Kurdish forces.

But the line from Downing Street has been consistent: Britain’s focus is on humanitarian assistance rather than a combat role so the Prime Minister will not recall MPs.

Mr Cameron is still bruised by losing the vote on intervention in Syria – he does not want to risk another humiliation.

But there is another reason why British forces are unlikely to march into battle to save the Yazidis: next year is an election year.

Remember when Barack Obama refused to lead the air strikes in Libya, preferring to quietly support the British and French forces?

That was back in 2011. One year later, in 2012, the American public voted on who should be their next President.

Counterintuitively, a poll in the Times today shows support for British bombing of militants in Iraq is at 40% - that's up 3% compared to the same poll taken on Monday. It also shows 36% of those asked were opposed to action.

But that does not tell the whole story.

When George Bush declared a "war on terrorism" on September 21st 2001, his approval ratings jumped to an astonishing high of 90%.

In 2003, shortly before the invasion of Iraq, an Ipsos Mori poll showed that 56% of the British public supported Britain's involvement compared to 38% who opposed it.

That support – it hardly needs to be said – crumbled away to leave a mistrust in politicians that still resides to this day.